While solar cell technology has steadily improved, a substantial leap is generally needed to achieve costs of, for example, $1 per watt and below, which will enable truly broad commercialization. Photovoltaics with conductive polymers as the p-type semiconductor, that are solution processed and printed in a large scale roll-to-roll process, have the potential to achieve this goal. Polymers are needed with the unique ability to be tailored to meet application requirements. Specifically, by tuning the band gap, energy levels, and processability, polymers are needed which can be the key to unlocking applications for solar cell technology.
A need exists for better photovoltaic devices which can be commercially processed well, can be synthetically tailored, can be reasonably priced, and can provide good efficiency and stability. In particular, polymer materials can provide good processability and synthetic versatility. Also needed is better use of nanotechnology and nanomaterials to control the polymer-based heterojunction.
US Patent Publication 2005/0022865 to Robeson et al. describes photovoltaic systems based on higher glass transition temperature polymers.